1 /*
   2  * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/stackMapFrame.hpp"
  27 #include "classfile/verifier.hpp"
  28 #include "memory/resourceArea.hpp"
  29 #include "oops/oop.inline.hpp"
  30 #include "oops/symbol.hpp"
  31 #include "runtime/handles.inline.hpp"
  32 #include "utilities/globalDefinitions.hpp"
  33 
  34 StackMapFrame::StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* v) :
  35                       _offset(0), _locals_size(0), _stack_size(0),
  36                       _stack_mark(0), _flags(0), _max_locals(max_locals),
  37                       _max_stack(max_stack), _verifier(v) {
  38   Thread* thr = v->thread();
  39   _locals = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_locals);
  40   _stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_stack);
  41   int32_t i;
  42   for(i = 0; i < max_locals; i++) {
  43     _locals[i] = VerificationType::bogus_type();
  44   }
  45   for(i = 0; i < max_stack; i++) {
  46     _stack[i] = VerificationType::bogus_type();
  47   }
  48 }
  49 
  50 StackMapFrame* StackMapFrame::frame_in_exception_handler(u1 flags) {
  51   Thread* thr = _verifier->thread();
  52   VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, 1);
  53   StackMapFrame* frame = new StackMapFrame(_offset, flags, _locals_size, 0, _max_locals, _max_stack, _locals, stack, _verifier);
  54   return frame;
  55 }
  56 
  57 void StackMapFrame::initialize_object(
  58     VerificationType old_object, VerificationType new_object) {
  59   int32_t i;
  60   for (i = 0; i < _max_locals; i++) {
  61     if (_locals[i].equals(old_object)) {
  62       _locals[i] = new_object;
  63     }
  64   }
  65   for (i = 0; i < _stack_size; i++) {
  66     if (_stack[i].equals(old_object)) {
  67       _stack[i] = new_object;
  68     }
  69   }
  70   if (old_object == VerificationType::uninitialized_this_type()) {
  71     // "this" has been initialized - reset flags
  72     _flags = 0;
  73   }
  74 }
  75 
  76 VerificationType StackMapFrame::set_locals_from_arg(
  77     const methodHandle m, VerificationType thisKlass, TRAPS) {
  78   SignatureStream ss(m->signature());
  79   int init_local_num = 0;
  80   if (!m->is_static()) {
  81     init_local_num++;
  82     // add one extra argument for instance method
  83     if (m->name()->equals(vmSymbols::object_initializer_name()) &&
  84        thisKlass.name()->not_equals(vmSymbols::java_lang_Object())) {
  85       _locals[0] = VerificationType::uninitialized_this_type();
  86       _flags |= FLAG_THIS_UNINIT;
  87     } else {
  88       _locals[0] = thisKlass;
  89     }
  90   }
  91 
  92   // local num may be greater than size of parameters because long/double occupies two slots
  93   while(!ss.at_return_type()) {
  94     init_local_num += _verifier->change_sig_to_verificationType(
  95       &ss, &_locals[init_local_num],
  96       CHECK_VERIFY_(verifier(), VerificationType::bogus_type()));
  97     ss.next();
  98   }
  99   _locals_size = init_local_num;
 100 
 101   switch (ss.type()) {
 102     case T_OBJECT:
 103     case T_ARRAY:
 104     {
 105       Symbol* sig = ss.as_symbol(CHECK_(VerificationType::bogus_type()));
 106       // Create another symbol to save as signature stream unreferences
 107       // this symbol.
 108       Symbol* sig_copy =
 109         verifier()->create_temporary_symbol(sig, 0, sig->utf8_length(),
 110                                  CHECK_(VerificationType::bogus_type()));
 111       assert(sig_copy->equals(sig), "symbols don't match");
 112       return VerificationType::reference_type(sig_copy);
 113     }
 114     case T_INT:     return VerificationType::integer_type();
 115     case T_BYTE:    return VerificationType::byte_type();
 116     case T_CHAR:    return VerificationType::char_type();
 117     case T_SHORT:   return VerificationType::short_type();
 118     case T_BOOLEAN: return VerificationType::boolean_type();
 119     case T_FLOAT:   return VerificationType::float_type();
 120     case T_DOUBLE:  return VerificationType::double_type();
 121     case T_LONG:    return VerificationType::long_type();
 122     case T_VOID:    return VerificationType::bogus_type();
 123     default:
 124       ShouldNotReachHere();
 125   }
 126   return VerificationType::bogus_type();
 127 }
 128 
 129 void StackMapFrame::copy_locals(const StackMapFrame* src) {
 130   int32_t len = src->locals_size() < _locals_size ?
 131     src->locals_size() : _locals_size;
 132   for (int32_t i = 0; i < len; i++) {
 133     _locals[i] = src->locals()[i];
 134   }
 135 }
 136 
 137 void StackMapFrame::copy_stack(const StackMapFrame* src) {
 138   int32_t len = src->stack_size() < _stack_size ?
 139     src->stack_size() : _stack_size;
 140   for (int32_t i = 0; i < len; i++) {
 141     _stack[i] = src->stack()[i];
 142   }
 143 }
 144 
 145 // Returns the location of the first mismatch, or 'len' if there are no
 146 // mismatches
 147 int StackMapFrame::is_assignable_to(
 148     VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
 149   int32_t i = 0;
 150   for (i = 0; i < len; i++) {
 151     if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) {
 152       break;
 153     }
 154   }
 155   return i;
 156 }
 157 
 158 bool StackMapFrame::has_flag_match_exception(
 159     const StackMapFrame* target) const {
 160   // We allow flags of {UninitThis} to assign to {} if-and-only-if the
 161   // target frame does not depend upon the current type.
 162   // This is slightly too strict, as we need only enforce that the
 163   // slots that were initialized by the <init> (the things that were
 164   // UninitializedThis before initialize_object() converted them) are unused.
 165   // However we didn't save that information so we'll enforce this upon
 166   // anything that might have been initialized.  This is a rare situation
 167   // and javac never generates code that would end up here, but some profilers
 168   // (such as NetBeans) might, when adding exception handlers in <init>
 169   // methods to cover the invokespecial instruction.  See 7020118.
 170 
 171   assert(max_locals() == target->max_locals() &&
 172          stack_size() == target->stack_size(), "StackMap sizes must match");
 173 
 174   VerificationType top = VerificationType::top_type();
 175   VerificationType this_type = verifier()->current_type();
 176 
 177   if (!flag_this_uninit() || target->flags() != 0) {
 178     return false;
 179   }
 180 
 181   for (int i = 0; i < target->locals_size(); ++i) {
 182     if (locals()[i] == this_type && target->locals()[i] != top) {
 183       return false;
 184     }
 185   }
 186 
 187   for (int i = 0; i < target->stack_size(); ++i) {
 188     if (stack()[i] == this_type && target->stack()[i] != top) {
 189       return false;
 190     }
 191   }
 192 
 193   return true;
 194 }
 195 
 196 bool StackMapFrame::is_assignable_to(
 197     const StackMapFrame* target, bool is_exception_handler,
 198     ErrorContext* ctx, TRAPS) const {
 199   if (_max_locals != target->max_locals()) {
 200     *ctx = ErrorContext::locals_size_mismatch(
 201         _offset, (StackMapFrame*)this, (StackMapFrame*)target);
 202     return false;
 203   }
 204   if (_stack_size != target->stack_size()) {
 205     *ctx = ErrorContext::stack_size_mismatch(
 206         _offset, (StackMapFrame*)this, (StackMapFrame*)target);
 207     return false;
 208   }
 209   // Only need to compare type elements up to target->locals() or target->stack().
 210   // The remaining type elements in this state can be ignored because they are
 211   // assignable to bogus type.
 212   int mismatch_loc;
 213   mismatch_loc = is_assignable_to(
 214     _locals, target->locals(), target->locals_size(), THREAD);
 215   if (mismatch_loc != target->locals_size()) {
 216     *ctx = ErrorContext::bad_type(target->offset(),
 217         TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
 218         TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
 219     return false;
 220   }
 221   mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
 222   if (mismatch_loc != _stack_size) {
 223     *ctx = ErrorContext::bad_type(target->offset(),
 224         TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
 225         TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
 226     return false;
 227   }
 228 
 229   bool match_flags = (_flags | target->flags()) == target->flags();
 230   if (match_flags || is_exception_handler && has_flag_match_exception(target)) {
 231     return true;
 232   } else {
 233     *ctx = ErrorContext::bad_flags(target->offset(),
 234         (StackMapFrame*)this, (StackMapFrame*)target);
 235     return false;
 236   }
 237 }
 238 
 239 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
 240   if (_stack_size <= 0) {
 241     verifier()->verify_error(
 242         ErrorContext::stack_underflow(_offset, this),
 243         "Operand stack underflow");
 244     return VerificationType::bogus_type();
 245   }
 246   VerificationType top = _stack[--_stack_size];
 247   bool subtype = type.is_assignable_from(
 248     top, verifier(), false, CHECK_(VerificationType::bogus_type()));
 249   if (!subtype) {
 250     verifier()->verify_error(
 251         ErrorContext::bad_type(_offset, stack_top_ctx(),
 252             TypeOrigin::implicit(type)),
 253         "Bad type on operand stack");
 254     return VerificationType::bogus_type();
 255   }
 256   return top;
 257 }
 258 
 259 VerificationType StackMapFrame::get_local(
 260     int32_t index, VerificationType type, TRAPS) {
 261   if (index >= _max_locals) {
 262     verifier()->verify_error(
 263         ErrorContext::bad_local_index(_offset, index),
 264         "Local variable table overflow");
 265     return VerificationType::bogus_type();
 266   }
 267   bool subtype = type.is_assignable_from(_locals[index],
 268     verifier(), false, CHECK_(VerificationType::bogus_type()));
 269   if (!subtype) {
 270     verifier()->verify_error(
 271         ErrorContext::bad_type(_offset,
 272           TypeOrigin::local(index, this),
 273           TypeOrigin::implicit(type)),
 274         "Bad local variable type");
 275     return VerificationType::bogus_type();
 276   }
 277   if(index >= _locals_size) { _locals_size = index + 1; }
 278   return _locals[index];
 279 }
 280 
 281 void StackMapFrame::get_local_2(
 282     int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
 283   assert(type1.is_long() || type1.is_double(), "must be long/double");
 284   assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
 285   if (index >= _locals_size - 1) {
 286     verifier()->verify_error(
 287         ErrorContext::bad_local_index(_offset, index),
 288         "get long/double overflows locals");
 289     return;
 290   }
 291   bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK);
 292   if (!subtype) {
 293     verifier()->verify_error(
 294         ErrorContext::bad_type(_offset,
 295             TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
 296         "Bad local variable type");
 297   } else {
 298     subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK);
 299     if (!subtype) {
 300       /* Unreachable? All local store routines convert a split long or double
 301        * into a TOP during the store.  So we should never end up seeing an
 302        * orphaned half.  */
 303       verifier()->verify_error(
 304           ErrorContext::bad_type(_offset,
 305               TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
 306           "Bad local variable type");
 307     }
 308   }
 309 }
 310 
 311 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
 312   assert(!type.is_check(), "Must be a real type");
 313   if (index >= _max_locals) {
 314     verifier()->verify_error(
 315         ErrorContext::bad_local_index(_offset, index),
 316         "Local variable table overflow");
 317     return;
 318   }
 319   // If type at index is double or long, set the next location to be unusable
 320   if (_locals[index].is_double() || _locals[index].is_long()) {
 321     assert((index + 1) < _locals_size, "Local variable table overflow");
 322     _locals[index + 1] = VerificationType::bogus_type();
 323   }
 324   // If type at index is double_2 or long_2, set the previous location to be unusable
 325   if (_locals[index].is_double2() || _locals[index].is_long2()) {
 326     assert(index >= 1, "Local variable table underflow");
 327     _locals[index - 1] = VerificationType::bogus_type();
 328   }
 329   _locals[index] = type;
 330   if (index >= _locals_size) {
 331 #ifdef ASSERT
 332     for (int i=_locals_size; i<index; i++) {
 333       assert(_locals[i] == VerificationType::bogus_type(),
 334              "holes must be bogus type");
 335     }
 336 #endif
 337     _locals_size = index + 1;
 338   }
 339 }
 340 
 341 void StackMapFrame::set_local_2(
 342     int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
 343   assert(type1.is_long() || type1.is_double(), "must be long/double");
 344   assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
 345   if (index >= _max_locals - 1) {
 346     verifier()->verify_error(
 347         ErrorContext::bad_local_index(_offset, index),
 348         "Local variable table overflow");
 349     return;
 350   }
 351   // If type at index+1 is double or long, set the next location to be unusable
 352   if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
 353     assert((index + 2) < _locals_size, "Local variable table overflow");
 354     _locals[index + 2] = VerificationType::bogus_type();
 355   }
 356   // If type at index is double_2 or long_2, set the previous location to be unusable
 357   if (_locals[index].is_double2() || _locals[index].is_long2()) {
 358     assert(index >= 1, "Local variable table underflow");
 359     _locals[index - 1] = VerificationType::bogus_type();
 360   }
 361   _locals[index] = type1;
 362   _locals[index+1] = type2;
 363   if (index >= _locals_size - 1) {
 364 #ifdef ASSERT
 365     for (int i=_locals_size; i<index; i++) {
 366       assert(_locals[i] == VerificationType::bogus_type(),
 367              "holes must be bogus type");
 368     }
 369 #endif
 370     _locals_size = index + 2;
 371   }
 372 }
 373 
 374 TypeOrigin StackMapFrame::stack_top_ctx() {
 375   return TypeOrigin::stack(_stack_size, this);
 376 }
 377 
 378 void StackMapFrame::print_on(outputStream* str) const {
 379   str->indent().print_cr("bci: @%d", _offset);
 380   str->indent().print_cr("flags: {%s }",
 381       flag_this_uninit() ? " flagThisUninit" : "");
 382   str->indent().print("locals: {");
 383   for (int32_t i = 0; i < _locals_size; ++i) {
 384     str->print(" ");
 385     _locals[i].print_on(str);
 386     if (i != _locals_size - 1) {
 387       str->print(",");
 388     }
 389   }
 390   str->print_cr(" }");
 391   str->indent().print("stack: {");
 392   for (int32_t j = 0; j < _stack_size; ++j) {
 393     str->print(" ");
 394     _stack[j].print_on(str);
 395     if (j != _stack_size - 1) {
 396       str->print(",");
 397     }
 398   }
 399   str->print_cr(" }");
 400 }